decodeURIComponent should throw URIError for malformed surrogate sequence %ED%BF%BF

[ayuan0828]

Description

This test verifies compliance with ECMA-262 requirements on URIError handling. I thought maybe this test case could be added to the test case set?

Testcase

assert.throws(
  URIError,
  function() {
    decodeURIComponent('%ED%BF%BF');
  },
  'Invalid UTF-8 sequence %ED%BF%BF should trigger URIError'
);

Output

Expected behavior: Throw URIError
XS Engine behavior ([Issue #1464](Moddable-OpenSource/moddable#1464)): Returns string "���"

[ptomato]

Thanks! Please feel free to open a PR with that test case. We probably need a similar one for decodeURI as well.

You could also consider including several types of bad UTF-8 data as detailed in this Stackoverflow post: https://stackoverflow.com/a/1319229/172999